let promise = new Promise(function executor(resolve,reject){
    resolve(1);
});
/* let promise2 = promise
.then((value)=>{
    console.log('a',value);
    return 2;
})
let promise3 = promise2.then((value)=>{
    console.log('b',value);
    return 3;
})
promise3.then((value)=>{
    console.log('c',value);
}) */

promise
.then((value)=>{
    console.log('a',value);
    return 2;
})
.then((value)=>{
    console.log('b',value);
    return 3;
})
.then((value)=>{
    console.log('c',value);
});

